TY - JOUR
T1 - Deep L′- and M-band imaging for planets around Vega and ε Eridani
AU - Heinze, A. N.
AU - Hinz, Philip M
AU - Kenworthy, Matthew
AU - Miller, Douglas
AU - Sivanandam, Suresh
PY - 2008/11/20
Y1 - 2008/11/20
N2 - We have obtained deep adaptive optics (AO) images of Vega and ε Eri to search for planetary mass companions. We observed at the MMT in the L′ (3.8 μm) and M (4.8 μm) bands using Clio, a recently commissioned imager optimized for these wavelengths. Observing at these long wavelengths represents a departure from the H band (1.65 μm) more commonly used for AO imaging searches for extrasolar planets. The long wavelengths offer better predicted planet/star flux ratios and cleaner (higher Strehl) AO images at the cost of lower diffraction-limited resolution and higher sky background. We have not detected any planets or planet candidates around Vega or ε Eri. We report the sensitivities obtained around both stars, which correspond to upper limits on any planetary companions which may exist. The sensitivities of our L′- and M-band observations are comparable to those of the best H-regime observations of these stars. For ε Eri, our M-band observations deliver considerably better sensitivity to close-in planets than any previously published results, and we show that the M band is by far the best wavelength choice for attempts at ground-based AO imaging of the known planet ε Eri b. The Clio camera itself, with MMTAO, may be capable of detecting ε Eri b at its 2010 apastron, given a multinight observing campaign. Clio appears to be the only currently existing AO imager that has a realistic possibility of detecting ε Eri b.
AB - We have obtained deep adaptive optics (AO) images of Vega and ε Eri to search for planetary mass companions. We observed at the MMT in the L′ (3.8 μm) and M (4.8 μm) bands using Clio, a recently commissioned imager optimized for these wavelengths. Observing at these long wavelengths represents a departure from the H band (1.65 μm) more commonly used for AO imaging searches for extrasolar planets. The long wavelengths offer better predicted planet/star flux ratios and cleaner (higher Strehl) AO images at the cost of lower diffraction-limited resolution and higher sky background. We have not detected any planets or planet candidates around Vega or ε Eri. We report the sensitivities obtained around both stars, which correspond to upper limits on any planetary companions which may exist. The sensitivities of our L′- and M-band observations are comparable to those of the best H-regime observations of these stars. For ε Eri, our M-band observations deliver considerably better sensitivity to close-in planets than any previously published results, and we show that the M band is by far the best wavelength choice for attempts at ground-based AO imaging of the known planet ε Eri b. The Clio camera itself, with MMTAO, may be capable of detecting ε Eri b at its 2010 apastron, given a multinight observing campaign. Clio appears to be the only currently existing AO imager that has a realistic possibility of detecting ε Eri b.
KW - Instrumentation: adaptive optics
KW - Planetary systems
KW - Stars: individual (Vega, ε Eridani)
KW - Techniques: image processing
UR - http://www.scopus.com/inward/record.url?scp=55849137300&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=55849137300&partnerID=8YFLogxK
U2 - 10.1086/592100
DO - 10.1086/592100
M3 - Article
AN - SCOPUS:55849137300
VL - 688
SP - 583
EP - 596
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
ER -